The US gets away with pellet shooting guns because of the second amendment of the Constitution which gives the people the right to bear arms. The only thing that is against the law is machine guns.
I was thinking how to make black smoke also but can't think of any way yet but while my grandchildren were here I thought of ways to try.
I have a Panzer tank that shoots pellets and makes a cannon noise and the tank recoils and with oil has smoke. The barrel goes up and down and rotates 320 degrees. It has machine gun and engine noise to boot.
Now that the kids are gone I am going to take it apart to see what I can use on my Delta Queen

Hi all

This US site which is concerned with Civil War models has some useful stuff on these areas.

It describes how to modify servos to give continuous rotation (and even direct drive) of turrets, how to make guns that fire BB's etc.

http://walternelson.com/ironclads.pdf

Cheers

Bernie

Am on the return trip to California and while in Los Angeles I stopped in at Harbor Models to see their smoke generator and discuss other boating subjects. When hooked to the motor it will produce smoke according to the speed.
I also bought his steam engine sound module which with amplifier gives out a great speed controlled sound and also a bell ringing sound. Am planning to play the music with a mp3 player.
I had my granddaughter with me and after I finished she said out loud "good, the grand fathers are done talking"

I have known modelers use party poppers as the smoke and bang to simulate gun fire. R.G.Y

While having my two grandchildren with me this summer I had to put off my boat and just when I thought I was free my mother in law had health issues and now it is temporally settled I am back to building.
The smoke generator from Harbor Models works like a charm but only runs for about 30 minutes before refill so I gave it thought while I figure out how to turn 6 rudders the same way without looking tacky while also using the bow thruster.
Last Thursday I figured out because I do not want to cut it apart, the only way was to build another box and to connect the two with a tube at the bottom so that the liquid would be equal in both tanks. the size of the extra box would determine how long it would work.
I hooked mine up and it went full speed for an hour and a half but then my battery which I had not charged since last year was dying so I know it has several hours of smoke in it.
The funny part of this was that Saturday I received my copy of Model Boats October 2012 and on page 60 is a steam generator and visiting their site I saw that they sell units to hook up to extend time.